I have a super c that was my grandfathers starting to do a mild restoration to get it back in working order to mow with. I have updated a few things and cleaned some parts. The tractor starts great and runs but when I take it up a hill or put any load on it it looses power and will bog down enough to die if I let it. Wondering where to start first to diagnose or best guess of issue? Any help would be greatly appreciated!